1. Field of the Invention
Embodiments of the present invention generally relate to fluid processing systems such as those in semiconductor manufacturing processes. More particularly, the invention relates to a system and method for dividing a flow of a process fluid or a mixture of process fluids in a predetermined flow ratio from a single inlet to multiple outlets.
2. Description of the Related Art
Fluid processing systems find applications in various industries, such as the semiconductor and pharmaceutical fields. In the semiconductor industry, for example, such systems are utilized in fabrication facilities where they are used to provide accurately metered quantities of fluid(s) to a substrate processing chamber. For example, such systems are typically used in processes such as chemical vapor deposition (CVD), high-density plasma chemical vapor deposition (HDPCVD), atomic layer deposition (ALD), etching, or the like.
In a typical fabrication facility the gases used in the fluid processing systems are typically stored in cylinders or tanks, which are connected to a gas panel via piping or conduit. The fluid processing system in the fabrication facility includes gas metering units such as valves, pressure sensors, mass flow controllers (MFCs) and filters. A plurality of fluid supplies are sometimes coupled to the MFC(s) to provide an accurately metered amount of fluid to a common manifold.
Various systems, apparatus, and methods have been devised in order to divide the flow of process fluids in a desired ratio. Such systems, apparatus, and methods typically make use of multiple MFCs to accurately control the desired flow division. However, the installation, operation, and maintenance costs for each MFC is relatively high. Additionally, the control systems adapted to control multiple MFC processes are complex to build. Moreover, each MFC is typically calibrated for a specific process fluid and, thus, do not operate properly for multiple process fluids or for complex mixtures of process fluids.
There is hence a need for an improved system and method for dividing the flow of a process fluid or a mixture of process fluids in a predetermined ratio from a single inlet to multiple outlets.